1. Field of the Invention
This invention relates to saws and machining slot cutters in which each tooth is mounted in the body of the saw or cutter in a removable cartridge for individual maintenance and replacement of the teeth.
2. Description of Prior Art
Saws and machining slot cutters for commercial and industrial usage sometimes have individually removable tooth cartridges mounted on the periphery of the saw or cutter body. Each cartridge holds one tooth. This allows replacement of teeth without replacement of the cutter body, and makes maintenance of the teeth easier. One disadvantage is the possibility that the cartridge may loosen during operation--an unsafe condition. A second disadvantage is that the cartridge and its mounting mechanism takes space, reducing the maximum number of teeth on the cutter in comparison to non-removable teeth. A third disadvantage is cost, since individual teeth, cartridges, and their associated mounting hardware greatly increase the complexity and number of parts in a cutter in comparison to non-removable teeth. A fourth disadvantage is the effort and skill required to install the cartridges properly in the cutter. Thus, what is needed is a removable cartridge mechanism with minimal size and complexity that is highly secure and easy to install properly. The present invention fills this need.
The following U.S. patents show earlier related inventions:
U.S. Pat. No. 4,257,302 (Heimbrand 1981) PA1 U.S. Pat. No. 424,263 (Bole 1890) PA1 U.S. Pat. No. 221,602 (Ohlen 1879) PA1 U.S. Pat. No. 205,042 (Brooke 1878) PA1 U.S. Pat. No. 146,680 (Husbands, Jr. 1874) PA1 U.S. Pat. No. 141,427 (Crookes 1873) PA1 U.S. Pat. No. 103,045 (Hiles 1870) PA1 U.S. Pat. No. 31,073 (Brown 1861)
For example, Heimbrand provides a cartridge mounted in an open-ended slot that converges toward the open end. The user must insert a cam between the cartridge and the cutter body, hold the cartridge in position, slide a tooth between the cartridge and cutter body opposite the cam, and hold the tooth and cartridge in position while locking the cam. This requires a high degree of manual dexterity. It also requires manual strength, since a cam provides less than 360 degrees of rotation between its loose and tight conditions, and thus cannot provide the high mechanical advantage of a screw. In Heimbrand, if the cam is not fully tightened, or works loose during operation, the tooth can fly out, releasing the cartridge as well.